Sparkleberry (Vaccinium arboreum)

Farkleberry, Huckleberry, Sparkleberry, Tree Sparkleberry, Winter Huckleberry

Farkleberry (Vaccinium arboreum) is a deciduous shrub that grows from 3.5 to 8 m tall. Its fragrant tiny bell-shaped flowers blossom from spring to summer followed by shiny inedible bluish-black berries. The dark green leaves of this small tree turn deep red in fall. It thrives in partial shade and attracts butterflies, birds and mammals.

I. Appearance and Characteristics 

Vaccinium arboreum (sparkleberry or farkleberry) is a species of Vaccinium native to the southeastern and south-central United States, from southern Virginia west to southeastern Nebraska, south to Florida and eastern Texas, and north to Illinois.

Vaccinium arboreum is a shrub (rarely a small tree) growing to 3–5 m (7.5-12.5 feet) rarely 9 m) (22.5 feet) tall, with a diameter at breast height of up to 35 cm (14 inches). The leaves are evergreen in the south of the range, but deciduous further north where winters are colder; they are oval-elliptic with an acute apex, 3–7 cm long and 2–4 cm broad, with a smooth or very finely toothed margin. Sparkleberry grows on sand dunes, hammocks, dry hillsides, meadows, and in rocky woods. It also grows on a variety of moist sites such as wet bottomlands and along creek banks.

The flowers are white, bell-shaped, and 3–4 mm (0.12-0.16 inches) in diameter with a five-lobed corolla, produced in racemes up to 5 cm (2 inches) long. The fruit is a round dry berry about 6 mm (0.24 inches) in diameter, green at first, black when ripe, edible but bitter and tough. They are eaten by various wildlife.

Because of its relative hardiness in comparison to other Vaccinium species, Vaccinium arboreum has been investigated as a potential rootstock for expanding the range of blueberry cultivation to less acidic soils(PH>6.0) and reducing the severity of bacterial leaf scorch.

II. How to Grow and Care

Sunlight

The farkleberry is a full sun plant. Insufficient sunlight affects its flowering and fruiting. When selecting a growing location, try to avoid placing your plants near large trees. The tree crown coverage not only affects light, but also reduces air circulation, making diseases much more likely.

Temperature

The farkleberry has many cultivated species that have a wide adaptability to different temperatures. However, cold temperatures (T < 7 ℃) during dormancy are vital to helping them bloom the following year. The Lowbush Blueberry and the Northern High Blueberry usually need more than 800 to 1000 chill hours in an environment below 7℃. The Rabbiteye farkleberry from the south also needs around 350 to 700 hours. It is important to pay attention to cold resistance and chill hours when selecting varieties.

The farkleberry has a fibrous root system with shallow root distribution. Like other Ericaceae species, its roots with symbiotic fungi absorb water and nutrients from the soil. Therefore, the farkleberry is neither drought-resistant nor flood-resistant, and requires careful adjustment of soil moisture.

Watering

Regular watering is needed to grow farkleberry. Since the sandy soil it prefers has low humidity and low water retention, irrigation should be done every two or three days during a hot summer. Deep watering may be required once a week. In total, farkleberry requires the amount of water equivalent to an average precipitation of 2.5 cm per week from germination to defoliation, and then around 4 cm from the beginning of fruit bearing to fruit harvesting. Water supply should be reduced from fall to enable the plant to enter dormancy in time.

Soil

Because the wild blueberries mostly grows on the edges of forests, they are accustomed to the acidic soil formed by dead branches and fallen leaves.Loose, acid soil (pH 3.8-5.5) with a good drainage performance and plenty of humus is best, with the optimum pH value being 4.5. Sandy soil and sandy loam are also preferred.

Soil acidity can be adjusted to cater to the farkleberry. If the pH of your soil is between 5.5 and 7.0, sphagnum peat can be applied at a 10 to 15 cm thickness into the 0 to 150 mm top-layer of soil, before being fully mixed in. Sphagnum peat not only improves soil acidity, but also significantly increases the content of humus. If the pH of your soil is higher than 7.0, a raised ridge bed can be built and filled with soil that has the correct acidity. Back-filling soil should be 20 to 30 cm higher than the ground plane, and all roots must be covered in the soil layer below 0 to 150 mm.

Fertilizing

The farkleberry is a plant that does not demand much fertilizer. However, if you are meeting soil acidity requirements and the leaves are losing their green color, or new shoots are growing extremely slowly, a nitrogen fertilizer should be considered. Ammonium nitrogen is the best kind of nitrogen fertilizer for a farkleberry.

After planting, young plants should be fertilized in early spring and late spring respectively. For adult plants, fertilizer can be applied every fall and winter after flowering. Each plant would benefit from an organic fertilizer or a compound fertilizer (N%-P2O5%-K2O%=15:15:15).

Excessive fertilization easily damages the farkleberry, and can even kill the whole plant. Forbidden fertilizer types include chlorine-containing fertilizer; nitrate nitrogen fertilizer; calcium-containing fertilizer.

Planting Instructions

Planting requirements for the farkleberry differ between varieties. Ideally, use bag seedlings that are two to three years old when planting a farkleberry, with the diameter of the base of the main stem being more than 5 mm.

If garden centers provide bare-root seedlings, these can be stored in a damp and dark environment before planting to keep them in dormancy. The criterion of “dampness” is that the roots must be kept moist, but not fully saturated. Ideal planting time is usually late winter or early spring, before the plant starts sprouting new buds. Soak the roots of bare-root seedlings in water for 3 or 4 hours before planting.

Two or more plants of different species, with the same fluorescence, can be planted at the same time. Pollination between different plants can increase the fruit setting rate, as well as the single fruit weight. For species with a larger plant shape, the spacing should be appropriately increased.

If you are planting farkleberry into a pot, place this in a shaded and well-ventilated room for a week, before moving it outdoors and resuming with normal care. If on sloping land, avoid planting in locations where cold air stagnates, so that the plant is protected from frost during flowering. Adequate irrigation should also be carried out after planting. Maintain an organic mulch at a thickness of 5 to 10 cm throughout the year after planting.

A mulch such as broken wood sawdust, peat, pine needles and fallen leaves can help maintain soil acidity. As acidic organic matter degrades every year, the pH value of your soil needs annual monitoring, with adjustments as needed. Once the pH value of the soil is higher than 5.5, the farkleberry roots cannot absorb iron, meaning that the edges of leaves will lose their green color and turn red. Growth will be stunted, and the plant could even die. An acid peat soil mixture, while useful, takes effect slowly. If there are signs of an iron deficiency during the growing season, a chelated iron foliar fertilizer can be sprayed and a sulfur powder can be used to adjust the pH value of the soil.

Pruning

Pruning of young plants: After planting, for the first two or three years, the flower buds should be completely removed in the spring. This will promote growth, improve lifespan and boost future fruit yield. Pinch off any spindly shoots during the growing season to increase the number of sprouting lateral branches, so as to expand the tree crown.

Fruiting plant pruning: From the third year after planting, the farkleberry should be pruned each year, before the sprouting of new buds in early spring. The annual branch bears fruits, and the stronger the branch is, the more fruits it bears. For mature plants, each cluster should retain 4 to 6 stems and 1 or 2 new branches each year, keeping the tree uniform and well-ventilated.

Because of the plant’s slow growth, pruning should be conservative. Excessive pruning will greatly affect the amount of fruits produced. Farkleberry has both creeping and erect branches, and the erect should be retained as much as possible when pruning.

Propagation

The farkleberry is best propagated through cuttings and division.

  • Cutting

Cuttings of hard branches is usually recommended for the highbush blueberries, while cuttings of tender branches is best for the rabbiteye blueberries. Both methods are acceptable for the lowbush blueberries.

Cuttings should be taken from plants that are robust and free from diseases and pests, ideally in the late spring or early summer. Annual vegetative branches with good maturity should be selected, about 20 cm long each. The rooting rate of the basal branches is significantly higher than that of the upper branches. Only take cuttings with buds, ensuring that the cut at the upper end of the branch is flat, while the cut at the lower part is oblique. Wet the soil and insert cuttings into the soil, with only one terminal bud exposed.

  • Division

Firstly, the stock plant should be dug out from the soil and its roots cleaned. Cut off the underground stem with clean sharp scissors and divide it into several plants. Fill the planting pit with a peat sand mixture with adjusted pH, then arrange the roots of the separated small plants and place them into the soil. Carefully wrap the roots with the soil mixture before filling in the hole.

III. Uses and Benefits 

Farkleberry grows as a shrub or small tree that makes an effective hedgerow, or can be mixed with other shrubs in a garden or woodland setting. Some varieties are deciduous, and others have evergreen leaves, but all produce a small dark berry in the fall that is an excellent animal food source in wildlife-friendly gardens.

IV. Harvesting and Storage

The farkleberry fruiting period can last for several weeks. Fruit ripens when its surface turns bluish black. Due to inconsistent ripening of fruits, they should be harvested in batches. Harvest once every 2 or 3 days in full fruit period, and once every 3 or 4 days in both the initial and final fruit period, completing your harvest before the frost.

Gloves (finger sleeves) should be worn when picking fruits to avoid damaging them, which would affect their appearance and storage potential. When picking ripe fruits, gently hold the berries and tweak them clockwise to keep the peel intact. This will also help to prolong their storage period.

Sparkleberry (Vaccinium arboreum) Details

Common name Farkleberry, Huckleberry, Sparkleberry, Tree Sparkleberry, Winter Huckleberry
Botanical name Vaccinium arboreum
Plant type Native Plant
Hardiness zone 7a, 7b, 8a, 8b, 9a, 9b
Growth rate Medium
Harvest time Fall
Height 8 ft. 0 in. - 15 ft. 0 in.
Width 8 ft. 0 in. - 15 ft. 0 in.
Sunlight Full sun (6 or more hours of direct sunlight a day)
Soil condition Loam (Silt)
Flower color White
Leaf color Green